Android Api 29 对文件和文件夹进行了重大更改。不允许使用外部存储，如下方法：
Environment.getExternalStorageDirectory() = /mnt/sdcard
Environment.getExternalStoragePublicDirectory(“test”) = /mnt/sdcard/test
只能使用内部存储
getExternalFilesDir(“test”) = /mnt/sdcard/Android/data/com.my.app/files/test
getExternalFilesDir(null) = /mnt/sdcard/Android/data/com.my.app/files
但谷歌官方给了一个后门，在AndroidManifest.xml文件中application节点中加上android:requestLegacyExternalStorage="true"属性才可以访问沙盒路径下的数据
原来的项目就要重新适配
Android开发:filePath放在哪个文件夹
Environment.getDataDirectory() = /data
Environment.getDownloadCacheDirectory() = /cache
外部存储
Environment.getExternalStorageDirectory() = /mnt/sdcard
Environment.getExternalStoragePublicDirectory(“test”) = /mnt/sdcard/test
Environment.getRootDirectory() = /system
getPackageCodePath() = /data/app/com.my.app-1.apk
getPackageResourcePath() = /data/app/com.my.app-1.apk
getCacheDir() = /data/data/com.my.app/cache
getDatabasePath(“test”) = /data/data/com.my.app/databases/test
getDir(“test”, Context.MODE_PRIVATE) = /data/data/com.my.app/app_test
getExternalCacheDir() = /mnt/sdcard/Android/data/com.my.app/cache
应用内部存储
getExternalFilesDir(“test”) = /mnt/sdcard/Android/data/com.my.app/files/test
getExternalFilesDir(null) = /mnt/sdcard/Android/data/com.my.app/files
getFilesDir() = /data/data/com.my.app/files
参考文章：
安卓Enviroment类的详解-CSDN博客
权限申请
11以上添加如下权限：
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE" />
代码动态申请
public final class PermissionActivity extends AppCompatActivity {
private static final int REQUEST_CODE = 1024;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestPermission();
}
private void requestPermission() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
// 先判断有没有权限
if (Environment.isExternalStorageManager()) {
writeFile();
} else {
Intent intent = new Intent(Settings.ACTION_MANAGE_APP_ALL_FILES_ACCESS_PERMISSION);
intent.setData(Uri.parse("package:" + context.getPackageName()));
startActivityForResult(intent, REQUEST_CODE);
}
} else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
// 先判断有没有权限
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED &&
ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
writeFile();
} else {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUEST_CODE);
}
} else {
writeFile();
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == REQUEST_CODE) {
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED &&
ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
writeFile();
} else {
ToastUtils.show("存储权限获取失败");
}
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == REQUEST_CODE && Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
if (Environment.isExternalStorageManager()) {
writeFile();
} else {
ToastUtils.show("存储权限获取失败");
}
}
}
/**
* 模拟文件写入
*/
private void writeFile() {
ToastUtils.show("写入文件成功");
}
}动态申请代码三方框架XXPermissions
XXPermissions.with(this)
// 不适配 Android 11 可以这样写
//.permission(Permission.Group.STORAGE)
// 适配 Android 11 需要这样写，这里无需再写 Permission.Group.STORAGE
.permission(Permission.MANAGE_EXTERNAL_STORAGE)
.request(new OnPermissionCallback() {
@Override
public void onGranted(List<String> permissions, boolean all) {
if (all) {
toast("获取存储权限成功");
}
}
@Override
public void onDenied(List<String> permissions, boolean never) {
if (never) {
toast("被永久拒绝授权，请手动授予存储权限");
// 如果是被永久拒绝就跳转到应用权限系统设置页面
XXPermissions.startPermissionActivity(MainActivity.this, permissions);
} else {
toast("获取存储权限失败");
}
}
});项目地址：GitHub - getActivity/XXPermissions: Android 权限请求框架，已适配 Android 14
// JitPack 远程仓库：https://jitpack.io
maven { url 'https://jitpack.io' }
// 权限请求框架：https://github.com/getActivity/XXPermissions
implementation 'com.github.getActivity:XXPermissions:18.5
# 表示将第三方库迁移到 AndroidX
android.enableJetifier = true
<manifest>
<application>
<!-- 告知 XXPermissions 当前项目已经适配了分区存储特性 -->
<meta-data
android:name="ScopedStorage"
android:value="true" />
</application>
</manifest>
框架扩展
XXPermissions.with(this)
// 申请单个权限
.permission(Permission.RECORD_AUDIO)
// 申请多个权限
.permission(Permission.Group.CALENDAR)
// 设置权限请求拦截器（局部设置）
//.interceptor(new PermissionInterceptor())
// 设置不触发错误检测机制（局部设置）
//.unchecked()
.request(new OnPermissionCallback() {
@Override
public void onGranted(@NonNull List<String> permissions, boolean allGranted) {
if (!allGranted) {
toast("获取部分权限成功，但部分权限未正常授予");
return;
}
toast("获取录音和日历权限成功");
}
@Override
public void onDenied(@NonNull List<String> permissions, boolean doNotAskAgain) {
if (doNotAskAgain) {
toast("被永久拒绝授权，请手动授予录音和日历权限");
// 如果是被永久拒绝就跳转到应用权限系统设置页面
XXPermissions.startPermissionActivity(context, permissions);
} else {
toast("获取录音和日历权限失败");
}
}
});其他API介绍
// 判断一个或多个权限是否全部授予了
XXPermissions.isGranted(Context context, String... permissions);
// 获取没有授予的权限
XXPermissions.getDenied(Context context, String... permissions);
// 判断某个权限是否为特殊权限
XXPermissions.isSpecial(String permission);
// 判断一个或多个权限是否被勾选了《不再询问》的选项（一定要在权限申请的回调方法中调用才有效果）
XXPermissions.isDoNotAskAgainPermissions(Activity activity, String... permissions);
// 跳转到应用权限设置页
XXPermissions.startPermissionActivity(Context context, String... permissions);
XXPermissions.startPermissionActivity(Activity activity, String... permissions);
XXPermissions.startPermissionActivity(Activity activity, String... permission, OnPermissionPageCallback callback);
XXPermissions.startPermissionActivity(Fragment fragment, String... permissions);
XXPermissions.startPermissionActivity(Fragment fragment, String... permissions, OnPermissionPageCallback callback);
// 设置不触发错误检测机制（全局设置）
XXPermissions.setCheckMode(false);
// 设置权限申请拦截器（全局设置）
XXPermissions.setInterceptor(new IPermissionInterceptor() {});
